Results of histological examinations of sentinel lymphatic nodes (SLN) obtained by rapid peroperative biopsy (RPB) are presented. Our first experience with 77 patients undergoing localized excision of axillary sentinel nodes is reported. Negative nodes were subsequently examined by means of immunohistochemistry of serial sectioned blocks. The aim of the study was to verify the percentage of identified metastases, and thus define the reliability of the RPB. At the same time we tried to determine the ratio of the negative biopsies of SLN, which were found positive subsequent to immunohistochemistry examination of serial sections, to the total amount of peroperative negative findings or a “false negativity”. Our results were compared with those recently published. Particular demands and possibilities of the method used are briefly discussed. In the group of 77 patients with breast cancer, the total number of 193 SLN were examined (average 2.5, in a patient ranging from 1 to 7). Out of all examined SLN, 45 patients (58.4%) were negative. Metastases were identified in 32 patients (41.6%). By rapid preoperative biopsy alone, metastases were found in 24%, which represents 75% sensitivity. The specificity was 100%. The following examination of serial sectioned specimens with or without immunohistochemistry showed 8 more patients with metastases, which represents the false negativity of 15.1%. The metastases found in all 8 patients were small micrometastases, isolated tumour cells or clusters of cells.

        Key words: breast carcinoma– sentinel lymph node – metastasis - intraoperative frozen-section biopsy